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Cerebrospinal Fluid Immunoglobulin Isotype Quantification (IgG, IgA, IgM)

Published: August 9, 2026Updated: August 16, 2026

This test measures the levels of three types of antibodies (IgG, IgA, IgM) in your cerebrospinal fluid (CSF), which is the fluid surrounding your brain and spinal cord. These antibodies can help diagnose or monitor conditions affecting the central nervous system.

Quick summary

["Ig antibodies in CSF may indicate immune-related brain or spinal cord issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
94662-4
Short code
C immitis IgG CSF Ql ID
Synonyms
C immitis IgG CSF Ql ID
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-diffusion
CPT
82784
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like headaches, neurological problems, or signs of an immune response in your brain or spinal cord. It can help identify conditions such as multiple sclerosis, infections, or inflammatory diseases.

What to Expect Before the Test

You’ll have a small needle inserted into your lumbar spine to collect CSF. The procedure is quick but may cause mild discomfort. No special preparation is needed, but inform your doctor about any medications or allergies.

What the Results Mean

Abnormal levels of IgG, IgA, or IgM in CSF can suggest conditions like autoimmune diseases, infections, or tumors. Your doctor will compare these results with your symptoms and other tests to diagnose the underlying issue.

Common Conditions Monitored

This test is often used to diagnose or track conditions like multiple sclerosis, Guillain-Barré syndrome, or certain infections (e.g., Lyme disease, meningitis). Elevated antibody levels may also indicate chronic inflammation or immune system dysfunction.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG/IgA/IgM in CSF

Frequently asked questions

What does an abnormal IgG/IgA/IgM level in CSF mean?
An abnormal result may indicate an immune response, infection, or inflammatory condition affecting your brain or spinal cord. Your doctor will review these results alongside your medical history and other tests to determine the cause.
How is this test different from blood antibody tests?
This test measures antibodies in CSF, which can reflect immune activity directly in the brain or spinal cord, unlike blood tests that show systemic antibody levels. CSF testing is more specific for central nervous system conditions.
Can lifestyle changes affect IgG/IgA/IgM levels in CSF?
While diet and exercise may influence immune function in general, IgG/IgA/IgM levels in CSF are primarily influenced by immune activity in the central nervous system. Your doctor will assess these results in the context of your overall health and symptoms.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy